iPhone hacker 'Comex', who engineered ways to hack Apple's mobile operating system, is no longer doing work for the company.

iPhone hacker 'Comex', who engineered ways to hack Apple's mobile operating system, is no longer doing work for the company.

"No point in delaying. As of last week, after about a year, I'm no longer associated with Apple," Comex said on Twitter.

He said the reason is that he failed to respond to an email from the company. It's rare but not unprecedented for someone who has a hacked a company's software to end up working there.

Later he said: "Now I feel like a big damn drama queen."

Comex is widely respected in the iPhone hacker realm for his work with the JailbreakMe applications, which exploited Apple's software to allow the installation of programs not vetted by the company in its App Store, a modification known as "jailbreaking." Apple doesn't like the practice, although it is legal in the US under an exception to the Digital Millennium Copyright Act.

In July 2011, Comex and his team released JailbreakMe 3.0, which used a pair of vulnerabilities to install unauthorised software on iOS versions 4.3.3 and prior. It worked with the first and second versions of the iPad and the iPhone.

Comex also delivered in July 2010 with JailbreakMe 2.0, which also used two vulnerabilities to exploit iOS. Apple patched the problems shortly after JailbreakMe 2.0 was released.

Elite iOS hackers are still at work to develop a jailbreak for iOS 6, Apple's latest version which was released last month. A "tethered" jailbreak exists, but an iOS 6 device must be connected to a computer when the attack occurs.

The more graceful way is to engineer an untethered jailbreak. iPhone hackers said at the Hack in the Box security conference last week that Apple has improved the security of iOS making it more difficult, but not impossible, to eventually perform an untethered jailbreak.